Comparative Animal Physiology (BIOL 3030) Exam II

Regarding the rates of oxygen diffusion in the body:

Diffusion is very rapid over very small distances, but slows greatly as distance increases

Each vertebrate hemoglobin protein can bind with up to:

4 molecules of oxygen

In vertebrate blood, oxygen is transported:

by hemoglobin inside red blood cells

Animals living in environments that are hypoxic or have low oxygen availability are more likely to have:

hemoglobin with a high affinity

A hemoglobin that binds oxygen very strongly would be described as having:

A high affinity and low P50

The relationship between oxygen saturation of hemoglobin and oxygen partial pressure is best described as:

Sigmoid

The respiratory pigment found in squid and most crabs is:

Hemocyanin

Which of the following are the three basic elements required for a circulatory system? (select three):

-Blood or hemolymph
-A pump
-Vascular system or tubes or sinuses

Respiratory pigments are:

Proteins that bind to oxygen

In larger and more active animals, respiratory gases are transported within the body by:

Convective transport

What property/parameter of oxygen in the blood will determine how much oxygen is bound to hemoglogin?

Oxygen partial pressure

The P50 of an oxygen dissociation curve is where:

The O2 partial pressure where hemoglobin is 50% saturated

Which of the following will cause a decrease (right shift) in Hb oxygen affinity? (Select all that apply)

- an increase in organic phosphates
- an increase in carbon dioxide
- an increase in temperature

A respiratory alkalosis would be due to:

hyperventilation of lungs

Most of the bicarbonate ends up transported in the blood plasma because of:

the chloride shift

In water as temperature increases, the pH will ______________ and relative alkalinity will ______________.

decrease, stay the same

Which of the following animals have a closed circulation? (select all that apply)

- squid
- earthworm
- fish

An artery is a blood vessel that:

carries blood away from the heart

A circulatory system where the exchange between blood and tissues occurs in open areas around the cells (e.g. sinuses) is called:

an open circulation

Which animals have a completely divided heart ventricle? (select all that apply)

- mammals
- birds

As the blood travels through the capillaries at the respiratory surface (e.g. lungs):

CO2 levels decrease and Hb affinity increases

Most of the conversion of carbon dioxide to bicarbonate in the tissue capillaries occurs:

In the red blood cells

When carbon dioxide is increased in water, the pH will:

decrease

If everything else stays the same, but aerobic metabolism in the tissues increases:

blood pH will decrease

Alkalosis is when:

blood pH is too high

The benefit of having the reaction forming bicarbonate inside the red blood cell is:

the carbon dioxide transport aids the oxygen release by the hemoglobin

The benefit of the "Bohr shift" is that:

more oxygen is delivered to respiring tissues

Total flow of blood from the heart (cardiac output) is the product of:

heart rate and stroke volume

Using Poiseuille's law, what will happen to blood pressure if resistance decreases, but blood flow stays the same?

The pressure gradient will decrease

Blood pressure will be lowest in the:

veins

As blood travels from arteries to capillaries to veins, the blood velocity:

decreases in the capillaries and increases in the veins

The depolarization of the cardiac muscle cells spreads from the atria to the ventricles through:

the atrio-ventricular node

The venous system of the systemic circulation acts as a:

volume reservoir

As arterial blood vessels branch and total cross-sectional area increases in the circulatory system, the total blood flow will ______________ and blood velocity will _______________.

stay the same, decrease

The arterial system of the systemic circulation functions as a:

pressure reservoir

Systole refers to:

the contraction period of the heart

The pocket valves:

prevent back flow of blood in the veins

Resistance is highest in the:

arterioles

According to the Frank-Starling law of the heart:

An increase in venous blood return to heart will increase stroke volume

The ejection of blood from the ventricle occurs:

between the QRS complex and the T-wave

The 'T-wave' of the electrocardiogram occurs when:

the ventricle repolarizes

Which of the following would cause an increase in heart rate? (select all that apply)

- An increase in circulating levels of epinephrine
- An increase in norepinephrine release from adrenergic nerves

A decrease in blood vessel radius, will have what effect on resistance?

Resistance will increase

Using Poiseuille's law, if vascular resistance increases, what will happen to blood flow, if the pressure stays the same?

Blood flow will decrease

What is the concentration of O2 in blood plasma at normal arterial pressure?

4 mL O2/L

What do respiratory pigments do?

bind oxygen at high PO2 and release it at low PO2

Which animals have hemocyanin as a respiratory pigment?

molluscs and arthropods

Hemocyanin appears _____ when unoxygenated and ____ when oxygenated.

clear, blue

Which animals have hemoglobin as a respiratory pigment?

most vertebrates

Hemoglobin appears ________ when oxygenated and _____________ when unoxygenated

bright red, dark maroon-red

Mammalian RBCs lack

a nucleus

Oxygen Dissociation/Equilibrium Curve

relationship b/w oxygen partial pressure and amount of O2 bound to hemoglobin

At ____ PO2, Hb binds a lot of O2 (ex: respiratory surface)

high

At ____ PO2, Hb releases a lot of O2 (ex: at tissues)

low

Low Affinity

Hb only saturated at high PO2

High Affinity

Hb saturated at low PO2

What is P50?

The PO2 causing 50% hemoglobin saturation

What movement on an O2 Dissociation Curve is observed from the Bohr Effect?

a right shift

Bohr Effect

- reduction in Hb O2 affinity with decreasing pH
- CO2 + H2O

A decrease in CO2 at the respiratory surface (lungs/gills) has what affect?

an increase in Hb O2 affinity, aids O2 uptake

What are the three forms that CO2 is transported in blood?

1) physically dissolved as molecular CO2
2) bound to proteins, including hemoglobin-carabamate groups
3) as bicarbonate (HCO3)

90% of CO2 in blood is transported in what form?

as bicarbonate (HCO3)

Chloride Shift

exchange of chloride ion for bicarbonate between the blood plasma and the RBC

What is the goal of acid-base balance in blood?

for acid production to be equal to acid excretion

Alkalosis

increase in pH

Acidosis

decrease in pH

Failure to maintain acid-base balance may lead to:

alkalosis and acidosis

Acid-base balance is achieved by: (select all that apply)

- changes in ventilation (change amount of CO2 loss)
- excretion (H+ filtration and HCO3 filtration by kidneys/gills/skin)

Respiratory Acidosis

-occurs during diving in air-breathing animals
-decrease in pH from decrease in ventilation

Respiratory Alkalosis

-hyperventilation
-decrease in CO2
-increase in pH

Metabolic Acidosis

-increase in anaerobic metabolism and lactic acid
-decrease in pH

Metabolic Alkalosis

-loss of acid
-increase in pH
-causes production of stomach acid (HCl) after a big meal , vomiting in excess

Alkalinity remains ________ as temperature increases

constant

Blood flow in an open circulatory system

- posterior to anterior dorsally
- anterior to posterior ventrally

Blood flow in a closed circulatory system

heart -> O2 source -> tissues -> heart

Blood flow in mammalian heart

right atrium -> right ventricle -> pulmonary arteries -> lungs -> pulmonary veins -> left atrium -> left ventricle -> aorta -> body capillaries

What happens in the heart and vascular system during systole? (select all that apply)

- contraction
- emptying
- depolarizing

What happens in the heart and vascular system during diastole? (select all that apply)

- relaxation
- refilling
- repolarizing

The atrium

collects blood from venous system and primes ventricular pump

The ventricle

is more muscular and generates pressure to pump blood to rest of body

Electrocardiogram (ECG / EKG)

summation of all the electrical activity of the heart

P-wave

atrial depolarization

QRS complex

ventricular depolarization

T-wave

ventricular repolarization

Cardiac Output (CO)

- volume of blood pumped per unit time from the ventricle (mL/min)
- is = HR * SV

Stroke Volume (SV)

- volume of blood ejected by each beat of the heart (ml/beat)
- is = end diastolic volume - end systolic volume

Acetylcohline (ACh)

- released from parasympathetic cholinergic nerve fibers (vagus nerve)
- slows heart rate (negative chronotropic effect)

Epinepherine (Adrenaline) & Norepinepherine (Noradrenaline)

- released from sympathetic adrenergic nerve fibers, or as circulating hormones
- increased heart rate (positive chronotropic effect)
- increase fore of contraction, increase SV

Poiseuille's Law Equation

- Q = ((P1-P2)/R)

Resistance Equation

- R = ((8ln)/πr^4)
- L and r are only non constants
- R is inversely proportional to r^4

Because total flow rate must be equal, the ________ is dependent of the total cross-sectional area of that part of the system/tube.

velocity

For tubes connected in series

longer tube = increase in total R

For tubes connected in parallel

more paths = decrease in total R

The ratio of change in volume to change in pressure (change in V / change in P) is called:

compliance

50% of blood volume in mammals is found in the

venous system

Blood pressure are measured relative to

ambient (atmospheric) pressure

Maximum arterial pressure is termed

systolic pressure

Minimum arterial pressure is termed

diastolic pressure

What is hydrostatic pressure?

the pressure in a column of fluid due to the force of gravity

Hydrostatic Pressure Equation

P = ρgh